题目

函数y=的最小正周期是(    )A.                B.               C.π                 D.2π 答案：解析：∵y===tan(+2x),∴T=.答案:B假设你是红星中学高三学生李华，请给你的外教Mr. Black写一封邮件，邀请他参加你们学校举行的英语读书会(reading circle)活动，邮件的内容包括：1. 介绍读书活动的相关信息（例如：时间、地点、活动目的、内容等）；2. 说明你发出邀请的原因；3. 询问对方的意向。注意： 1. 词数不少于100词；2. 开头和结尾已给出，不计入总词数。Dear Mr. Black,______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Yours,Li Hua